Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles
Newly acquired sediment cores and high-resolution seismic lines were studied in order to constrain the timing and mechanism of pockmark formation in the Loppa High area in the southwestern Barents Sea. The evolution of the pockmarks after their formation was also investigated, together with the poss...
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ftcquniportalfig:oai:figshare.com:article/13439162 2023-05-15T15:38:34+02:00 Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles Mauro Pau O Hammer S Chand 2014-09-01T00:00:00Z http://hdl.handle.net/10018/1239871 unknown https://figshare.com/articles/journal_contribution/Constraints_on_the_dynamics_of_pockmarks_in_the_SW_Barents_Sea_Evidence_from_gravity_coring_and_high-resolution_shallow_seismic_profiles/13439162 http://hdl.handle.net/10018/1239871 CQUniversity General 1.0 Geology not elsewhere classified pockmarks methane hydrate sediment cores seismic lines Barents Sea Text Journal contribution 2014 ftcquniportalfig 2022-08-05T12:24:56Z Newly acquired sediment cores and high-resolution seismic lines were studied in order to constrain the timing and mechanism of pockmark formation in the Loppa High area in the southwestern Barents Sea. The evolution of the pockmarks after their formation was also investigated, together with the possibility that they are currently active features. The cores retrieved within the pockmarks lack a layer of ice-rafted debris and an overlying sequence of laminated glaciomarine sediments that were deposited on the undisturbed seafloor at the inception of the Bølling interstadial (~. 15. cal. kyr. BP). The pockmarks are suggested to have formed in that period, probably due to climate change-induced destabilisation of methane hydrates and the subsequent release of free gas. The depressions deepened as a result of reduced sedimentation above active seeps. The pockmark cores contain a series of gravel-rich layers, which are attributed to the winnowing of sediment during episodic fluid venting activity. The seismic images reveal little disturbance of the most ancient sediments underneath the pockmarks, indicating that the pockmark chimneys are localised features and were not imaged. The Holocene marine sediment cover in the pockmarks is thinner than on the surrounding seafloor, indicating relatively low sedimentation rates inside the depressions. The gas seepage may thus have been active until the recent past, although no indications of present-day methane flux were found. © 2014 Elsevier B.V. Other Non-Article Part of Journal/Newspaper Barents Sea Loppa Methane hydrate CQUniversity: acquire Barents Sea Loppa ENVELOPE(22.351,22.351,70.240,70.240) |
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CQUniversity: acquire |
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Geology not elsewhere classified pockmarks methane hydrate sediment cores seismic lines Barents Sea |
spellingShingle |
Geology not elsewhere classified pockmarks methane hydrate sediment cores seismic lines Barents Sea Mauro Pau O Hammer S Chand Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles |
topic_facet |
Geology not elsewhere classified pockmarks methane hydrate sediment cores seismic lines Barents Sea |
description |
Newly acquired sediment cores and high-resolution seismic lines were studied in order to constrain the timing and mechanism of pockmark formation in the Loppa High area in the southwestern Barents Sea. The evolution of the pockmarks after their formation was also investigated, together with the possibility that they are currently active features. The cores retrieved within the pockmarks lack a layer of ice-rafted debris and an overlying sequence of laminated glaciomarine sediments that were deposited on the undisturbed seafloor at the inception of the Bølling interstadial (~. 15. cal. kyr. BP). The pockmarks are suggested to have formed in that period, probably due to climate change-induced destabilisation of methane hydrates and the subsequent release of free gas. The depressions deepened as a result of reduced sedimentation above active seeps. The pockmark cores contain a series of gravel-rich layers, which are attributed to the winnowing of sediment during episodic fluid venting activity. The seismic images reveal little disturbance of the most ancient sediments underneath the pockmarks, indicating that the pockmark chimneys are localised features and were not imaged. The Holocene marine sediment cover in the pockmarks is thinner than on the surrounding seafloor, indicating relatively low sedimentation rates inside the depressions. The gas seepage may thus have been active until the recent past, although no indications of present-day methane flux were found. © 2014 Elsevier B.V. |
format |
Other Non-Article Part of Journal/Newspaper |
author |
Mauro Pau O Hammer S Chand |
author_facet |
Mauro Pau O Hammer S Chand |
author_sort |
Mauro Pau |
title |
Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles |
title_short |
Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles |
title_full |
Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles |
title_fullStr |
Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles |
title_full_unstemmed |
Constraints on the dynamics of pockmarks in the SW Barents Sea: Evidence from gravity coring and high-resolution, shallow seismic profiles |
title_sort |
constraints on the dynamics of pockmarks in the sw barents sea: evidence from gravity coring and high-resolution, shallow seismic profiles |
publishDate |
2014 |
url |
http://hdl.handle.net/10018/1239871 |
long_lat |
ENVELOPE(22.351,22.351,70.240,70.240) |
geographic |
Barents Sea Loppa |
geographic_facet |
Barents Sea Loppa |
genre |
Barents Sea Loppa Methane hydrate |
genre_facet |
Barents Sea Loppa Methane hydrate |
op_relation |
https://figshare.com/articles/journal_contribution/Constraints_on_the_dynamics_of_pockmarks_in_the_SW_Barents_Sea_Evidence_from_gravity_coring_and_high-resolution_shallow_seismic_profiles/13439162 http://hdl.handle.net/10018/1239871 |
op_rights |
CQUniversity General 1.0 |
_version_ |
1766369632369770496 |